


Time, Curious Time

by SamFuckingWinchester



Category: The Infernal Devices Series - Cassandra Clare, The Shadowhunter Chronicles - Cassandra Clare
Genre: Bed-Wetting, Body Positivity, Bottom Will, Fluff, Fluff and Humor, Fluff and Smut, Idiots in Love, Kinktober 2020, Loud Sex, M/M, NSFW, One Shot, Parabatai, Pre-Canon, Rough Sex, Short & Sweet, Slash, Top Jem, Watersports, Wet & Messy, but not really, heronstairs
Language: English
Status: Completed
Published: 2020-10-17
Updated: 2020-10-17
Packaged: 2021-03-08 23:33:23
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,125
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27054976
Author URL: https://archiveofourown.org/users/SamFuckingWinchester/pseuds/SamFuckingWinchester
Summary: Will and Jem don't often have the Institute to themselves, so when it happens they tend to make the most of their time together .Just a short, NSFW one-shot featuring your favorite mid-century parabatai in a compromising situation.
Relationships: Jem Carstairs/Will Herondale
Comments: 2
Kudos: 30





	Time, Curious Time

**Author's Note:**

> The title of this one comes from Invisible String by one Taylor Swift. I'm working on a personal character exercise and decided this would work better for Will and Jem. It's gross and a little weird but we're just going to file it under "totally normal things that happen during sex" and "we're normalizing it so it's not weird or embarrassing". It doesn't exactly fit the kinktober perimeters so if that's all you're here for this might not be the fic for you. Enjoy, and don't make it weird.

On one hand, Will was grateful for the rare quiet of the Institute tonight; he and Jem often had to find other escapes around London in the dark if they wanted to get up to their usual desired nefarious activities, and their own beds were much more comfortable than the cold alley nearby or the grass by the river. But on nights like these, when the halls were mostly empty, the boys could do as they pleased. On the other hand, whatever messes resulting from the aforementioned activities were theirs to clean up, and Will detested cleanup. 

And that cleaning would be necessary tonight; Jem appeared to be feeling particularly feisty. He had Will pinned against the wall of his bedroom, shirt long-discarded in the chaos of books and clutter. The two more commonly occupied Jem’s room when the Institute was empty enough, but he’d argued nobody would notice whatever wreckage was left in their wake in Will’s quarters. His paratabai had a point, Will supposed, but he was fretting about one of them tripping at some point. Maybe he should tidy his room more often…

His train of thought was derailed by Jem’s teeth on the skin just below his jaw. He groaned, and that only spurred Jem further. He didn’t mind the marks left behind; nobody would ask. Will reached around him for something to grab before he slipped, pushing another stack of books off a table beside him. They clattered to the ground while Jem worked on a zipper, his mouth still otherwise preoccupied at Will’s throat. Will muttered a low curse and braced his shoulders against the wall. He also began a short quip about eagerness and them having all night, but Jem’s tongue at his navel cut it off sharply. And then he did lose his balance, sinking lower to the ground abruptly. Jem’s reflexes were remarkable even for a Shadowhunter, and his hands caught Will by the armpits. His grin was wicked but the light in his eyes was still warm. Without warning he pitched Will onto the mattress. 

“I’m well aware the night is young, William,” Jem murmured, and the gentle fondness with which he’d said Will’s full name spread the growing heat throughout his body. “I intend to take full advantage.” Jem had one hand firmly pressed into his sternum and the other finished discarding whatever clothing was left. Will reached up, grasping at the fabric of Jem’s shirt. The boy on top of him pulled away, edges of his mouth turned up in amusement. “It’s my turn tonight,” he said, tone comically polite given the circumstances. 

“I merely wish to see you,” Will replied softly. The tenderness of the request seemed to take Jem off guard. His grip loosened and he abandoned his own shirt. Will used his elbows to sit up and then steadied himself with Jem’s waist, planting his lips wherever he could reach before he was pushed back down. 

“Cheater,” was all Jem said. He finished removing his hunting gear while Will watched with renewed fascination; it was never a sight he’d grow tired of no matter how often he was privileged enough to bear witness. Jem blushed under his gaze the way he always did, and then the Shadowhunters crashed together again, lips brushing, fingers tangled and limbs taught. Though they had what seemed like endless hours, Jem was not interested in drawing out the preparation. He had always insisted on making sure Will was comfortable; arguments had ensued in the past about the subject but they’d abruptly ended after one warning: Jem was never to be used as an instrument for Will to punish himself. It was exactly the right thing to say, of course. In this way Jem would always get what we wanted from Will. 

But they both had preferences. When Jem was in charge, Will was more than happy to be shoved into walls and pinned against headboards, to be grabbed and bruised and bitten. In this way Will would always get what he wanted from Jem. 

He was all silver hair and blown pupils now as he flipped Will onto his stomach and locked their bodies together without fanfare, marveling at the way they fit like pieces of a puzzle, one soul and then sometimes one body, parts of Will that Jem knew as well as his own, or better, even. Will moaned and whimpered and gasped with abandon, relishing in the freedom to do so without fear of being caught. Jem was the quiet one; it had always been this way. Jem’s mouth found purchase behind Will’s ear, eliciting another nearly-animalistic sound, and he laughed in surprise. 

“You sound like a whore,” he muttered. Will chuckled with what breath he could find between the sharp snap of Jem’s hips. 

“Only for you.” His partner huffed as if he didn’t believe it, though they both knew it to be true; that there could never be another, not like this. 

Jem sat up to readjust his legs more comfortably and Will yelped in surprise, suddenly balling the sheets up between white knuckles. Jem felt an unfamiliar dampness when he set his hands back on the mattress to balance himself properly and froze. “Will?” It wasn’t blood. There was no red and the consistency wasn’t right, but it couldn’t be ejaculate either, and Jem stayed completely still, his mind racing. When Will groaned beneath him he loosened up slightly. It was all annoyance and no pleasure.

“By the Angel, I think you made me piss the bloody bed,” he muttered, moving as much as his body would allow while Jem was still inside him. Jem coughed, an attempt to hide the laugh that escaped from his chest before he had time to hold it in, but Will wasn’t fooled. He turned back to the boy above him and scowled. The flush on his skin ruined the effect.

“You what?”

“Oh you heard me, you bastard.” Despite his suddenly foul mood he didn’t seem to be in any pain, and there really wasn’t a smell, so Jem relaxed all of the muscles in his body and fell from his wrists to his elbows, closer to Will’s back. He planted a soft kiss on the other’s neck in apology. Jem was worried now, though he’d never admit it. He shuffled them to the side to avoid most of the mess and waited patiently, lips still pressed into Will’s skin, for whatever reaction was coming. Will just grumbled beneath him. 

“Don’t be upset, I’m sure it’s perfectly normal. I suppose we could ask someone, though I haven’t the faintest idea how we’d broach the topic. It honestly doesn’t matter in any case. You needn’t worry,” Jem droned on. He only faintly registered Will saying his name repeatedly. “Don’t be ashamed. It’s not like I’d ever tell a soul besides. Every part of you is still glorious to me,” he continued, babbling now. It was the most anxious Will could recall Jem being in a long while. 

“Jem,” he repeated. 

“I was just thinking—”

“James!” Will implored at top volume. Jem stopped spluttering and stared, mouth slightly ajar. Will’s eyes were closed most of the time they made love, he thought absently. There wasn’t often a moment to spare to get lost in the magnificent color. Despite the hours stretched out before them, there truly was never enough time. “ _Move_.”

James Carstairs didn’t need to be told twice. Will twisted one hand with Jem’s, interlocking their fingers again. He bent the other arm back as far as humanly possible, forcing the other body down so there was only skin against skin. Jem collapsed with a short exhale. He barely noticed the stain spread beneath them again, too focused on Will’s incoherent mumblings. He couldn’t understand much of it, catching only bits of Welsh, the occasional archaic curse word, and Jem’s name mixed with a repeated request for “more”. 

Then Will grew quiet, and the only sounds were the creaking of his bed and the heavy breaths between them. 

“Don’t leave me, please.” It was uttered into the sheets, muffled, so much that Jem couldn’t be sure he’d heard correctly. “Please,” Will whispered again. Jem tightened his grip around his paratabai’s chest and nuzzled his neck, slowing his pace for a moment. 

“Not tonight.” It was all he could promise. Will moaned in response. He squeezed the hand holding Jem’s and sighed. He requested Jem go faster, uncharacteristically shy, and his partner obliged without another word. The nonsensical cries started up once more, mostly Jem’s name over and over, like a curse or a prayer or both. Jem finished wordlessly and it was nearly blinding but through the haze Will begged him not to stop, and Jem couldn’t deny him anything at all, much less this wanting, this needing, what suddenly seemed so fragile though he couldn’t place the reason. Jem tugged Will’s body up so he sat in Jem’s lap with arms around his neck and his nose buried in Will’s hair, slick with sweat. Will’s pleas were nearly whines, high and keening and very much unlike the noises Jem had learned to interpret over the years. “What do you need?” he wondered. Will shook his head and fell forward into Jem again. He nearly jumped out of his skin when his hips skittered back down forcefully. He doubted they’d ever gone so far in before.

“ _That_ ,” he answered, completely breathless. Jem understood; the motion had practically knocked the wind out of him as well. 

“Go on, then,” he urged. 

But he could see Will was exhausted. Jem only had to thrust twice. Will’s climax ripped through him like a jolt of electricity, finishing with a mixture of a sob and a cough from deep in his chest. He sank down and Jem was only just fast enough to catch the other Shadowhunter and pull out before Will hurt himself. Neither of them would live that down, he thought with amusement. He would already be sore. With William out of harm’s way, Jem had a moment to absorb the fact that his chest and lap were soaked with various fluids he had no desire to name.

“For Heaven’s sake Will, how much water did you consume before we came up here?”

Will was lying on his back, eyes shut, pink lips upturned in pure bliss. Jem had never seen anything more ethereal. He might not have believed in damnation or the fiery pits of Hell, but he could watch this scene unfold every night and know there was a deity far beyond them who had favorites, and he would know William Herondale was one of them. Touching him was the closest James would ever actually get to praying. 

“I was absolutely parched!” Will protested, but his mouth never deviated from its affixed grin. After a minute he summoned the strength to sit up and observe the carnage. “Good God,” he mumbled, pale, inked skin flushed tomato red. 

“Do be careful. He might show up and smite us for our sins.”

Will flashed him an impish smile. “That was certainly worth going to Hell for, wouldn’t you agree?” Jem blushed too, despite himself, and it was answer enough. “I’m terribly sorry,” Will added, turning serious. His lovely expression soured and his azure eyes dimmed. He motioned to Jem’s chest, a faint sheen glinting off his skin from light of the lamp. 

“It’s quite alright. I rather believe I should be the one apologizing to you for the state of your sheets. It appeared to be my fault. All three times,” Jem added as Will’s gaze snapped to the bed. “Though it will likely be poor Sophie who has the privilege of laundering them.” Will didn’t respond to that remark. He rose too hastily, unsteady on his feet, and subsequently scrambled with the bedpost before fully righting himself. 

“Well, James, I’m starting to think you’ve knocked my equilibrium off.”

“Just one of my many talents,” he replied, following his paratabai towards the bathroom. 

“Speaking of talent, we’ve got hours yet before the others return. The wondrous thing about a shower is the lack of linen to ruin.” Jem choked on his own air. His coughing fit caused Will to turn immediately, but he waved the other boy off. 

“If we agree on one thing tonight, let it be that if whatever just happened occurs again, you’ll be seeing a doctor. I’m sure one of the Silent Brothers would be all too happy to help,” he offered after catching his breath. Will turned a shade of red Jem hadn’t believed a human could possibly be. He spun back around and kicked the door to the lavatory shut, cutting off Jem’s musical laughter with a sharp click.

**Author's Note:**

> Leave a comment if you enjoyed it, or if you didn't, I guess. Writing a close scene between two men without using the overdone adjectives is supremely difficult, but I aspire nonetheless.


End file.
